2-(2-甲基-1,3-二氧戊环-2-基)乙醛

反应条件: temp:0.00; pressure:0.00; stir:

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: 2-(2-methyl-1,3-dioxolan-2-yl)acetaldehyde (320 mg, 2.459 mmol) and (3-bromo-5-nitro-4-pyridyl)hydrazine (286.4 mg, 1.229 mmol) were heated under reflux in ethanol (2.864 mL) overnight. The reaction mixture was concentrated in vacuo and the residue was partitioned between DCM and a saturated aqueous sodium hydrogen carbonate solution. Combined organic extract was dried over MgSO4 and concentrated in vacuo to leave 3-bromo-4-(5-methyl-1H-pyrazol-1-yl)-5-nitropyridine as a yellow oil. (200 mg, 85%). MS (ES+) 284.9. The reaction mixture was concentrated in vacuo the residue was partitioned between DCM Combined organic extract was dried over MgSO4 concentrated in vacuo

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: 2-(2-methyl-1,3-dioxolan-2-yl)acetaldehyde (320 mg, 2.459 mmol) and (3-bromo-5-nitro-4-pyridyl)hydrazine (286.4 mg, 1.229 mmol) were heated under reflux in ethanol (2.864 mL) overnight. The reaction mixture was concentrated in vacuo and the residue was partitioned between DCM and a saturated aqueous sodium hydrogen carbonate solution. Combined organic extract was dried over MgSO4 and concentrated in vacuo to leave 3-bromo-4-(5-methyl-1H-pyrazol-1-yl)-5-nitropyridine as a yellow oil. (200 mg, 85%). MS (ES+) 284.9. The reaction mixture was concentrated in vacuo the residue was partitioned between DCM Combined organic extract was dried over MgSO4 concentrated in vacuo

反应条件: temp:20.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Pyridine (7.2 g) and chromic oxide (CrO3) (4.6 g) are added in small fractions to dichloromethane (150 cc) over 10 minutes. After 15 minutes' stirring at a temperature in the region of 20° C., 2,2-ethylenedioxy-4-hydroxybutane (0.85 g, 6.4 mmol) is added quickly as a solution in dichloromethane (2 cc). After 15 minutes' stirring at 20° C., the black, viscous precipitate is separated off by filtration through silica and is washed with ether. After evaporation of the solvents, 3,3-ethylenedioxybutanal (0.59 g) is obtained (B.P.0.4 =35° C.). the black, viscous precipitate is separated off by filtration through silica is washed with ether After evaporation of the solvents

反应条件: temp:20.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Pyridine (7.2 g) and chromic oxide (CrO3) (4.6 g) are added in small fractions to dichloromethane (150 cc) over 10 minutes. After 15 minutes' stirring at a temperature in the region of 20° C., 2,2-ethylenedioxy-4-hydroxybutane (0.85 g, 6.4 mmol) is added quickly as a solution in dichloromethane (2 cc). After 15 minutes' stirring at 20° C., the black, viscous precipitate is separated off by filtration through silica and is washed with ether. After evaporation of the solvents, 3,3-ethylenedioxybutanal (0.59 g) is obtained (B.P.0.4 =35° C.). the black, viscous precipitate is separated off by filtration through silica is washed with ether After evaporation of the solvents

反应条件: temp:-70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Anhydrous ethyl ether (11 cc) and 1-bromo-2-methyl-4-trimethylsilyloxy-1,3-butadiene (0.9 g) are introduced under an argon atmosphere into a 50-cc round-bottomed flask. This is cooled to -70° C. and then a solution (3.25 cc) of 1.65M tert-butyllithium in pentane is added over 10 minutes. The mixture is stirred at -70° C. for 100 minutes and 3,3-ethylenedioxybutanal (0.4 g) is then added in solution in anhydrous ethyl ether (4 cc). The temperature is allowed to rise to -30° C. and stirring is performed for 30 minutes. Further stirring is performed for 20 minutes at -20° C. and then the mixture is cooled to -60° C. N Hydrochloric acid (11.5 cc) is added over 20 minutes. The temperature is allowed to rise to about 20° C. After the reaction mixture has been taken up with ether and water and the organic phases have been dried over magnesium sulphate, and after flash chromatography, 7,7-ethylenedioxy-3-methyl-2,4-octadienal (0.33 g) is obtained, its characteristics being as follows: to rise to -30° C. stirring is performed for 30 minutes Further stirring is performed for 20 minutes at -20° C. the mixture is cooled to -60° C to rise to about 20° C the organic phases have been dried over magnesium sulphate

反应条件: temp:-70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Anhydrous ethyl ether (11 cc) and 1-bromo-2-methyl-4-trimethylsilyloxy-1,3-butadiene (0.9 g) are introduced under an argon atmosphere into a 50-cc round-bottomed flask. This is cooled to -70° C. and then a solution (3.25 cc) of 1.65M tert-butyllithium in pentane is added over 10 minutes. The mixture is stirred at -70° C. for 100 minutes and 3,3-ethylenedioxybutanal (0.4 g) is then added in solution in anhydrous ethyl ether (4 cc). The temperature is allowed to rise to -30° C. and stirring is performed for 30 minutes. Further stirring is performed for 20 minutes at -20° C. and then the mixture is cooled to -60° C. N Hydrochloric acid (11.5 cc) is added over 20 minutes. The temperature is allowed to rise to about 20° C. After the reaction mixture has been taken up with ether and water and the organic phases have been dried over magnesium sulphate, and after flash chromatography, 7,7-ethylenedioxy-3-methyl-2,4-octadienal (0.33 g) is obtained, its characteristics being as follows: to rise to -30° C. stirring is performed for 30 minutes Further stirring is performed for 20 minutes at -20° C. the mixture is cooled to -60° C to rise to about 20° C the organic phases have been dried over magnesium sulphate

反应条件: temp:-70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Anhydrous ethyl ether (11 cc) and 1-bromo-2-methyl-4-trimethylsilyloxy-1,3-butadiene (0.9 g) are introduced under an argon atmosphere into a 50-cc round-bottomed flask. This is cooled to -70° C. and then a solution (3.25 cc) of 1.65M tert-butyllithium in pentane is added over 10 minutes. The mixture is stirred at -70° C. for 100 minutes and 3,3-ethylenedioxybutanal (0.4 g) is then added in solution in anhydrous ethyl ether (4 cc). The temperature is allowed to rise to -30° C. and stirring is performed for 30 minutes. Further stirring is performed for 20 minutes at -20° C. and then the mixture is cooled to -60° C. N Hydrochloric acid (11.5 cc) is added over 20 minutes. The temperature is allowed to rise to about 20° C. After the reaction mixture has been taken up with ether and water and the organic phases have been dried over magnesium sulphate, and after flash chromatography, 7,7-ethylenedioxy-3-methyl-2,4-octadienal (0.33 g) is obtained, its characteristics being as follows: to rise to -30° C. stirring is performed for 30 minutes Further stirring is performed for 20 minutes at -20° C. the mixture is cooled to -60° C to rise to about 20° C the organic phases have been dried over magnesium sulphate

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: 2-(2-methyl-1,3-dioxolan-2-yl)acetaldehyde (320 mg, 2.459 mmol) and (3-bromo-5-nitro-4-pyridyl)hydrazine (286.4 mg, 1.229 mmol) were heated under reflux in ethanol (2.864 mL) overnight. The reaction mixture was concentrated in vacuo and the residue was partitioned between DCM and a saturated aqueous sodium hydrogen carbonate solution. Combined organic extract was dried over MgSO4 and concentrated in vacuo to leave 3-bromo-4-(5-methyl-1H-pyrazol-1-yl)-5-nitropyridine as a yellow oil. (200 mg, 85%). MS (ES+) 284.9. The reaction mixture was concentrated in vacuo the residue was partitioned between DCM Combined organic extract was dried over MgSO4 concentrated in vacuo